The following line passes through point $(1, -9)$ : $y = -4 x + b$ What is the value of the $y$ -intercept $b$ ?
Explanation: Substituting $(1, -9)$ into the equation gives: $-9 = -4 \cdot 1 + b$ $-9 = -4 + b$ $b = -9 + 4$ $b = -5$ Plugging in $-5$ for $b$, we get $y = -4 x - 5$. ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${10}$ ${\llap{-}2}$ ${\llap{-}3}$ ${\llap{-}4}$ ${\llap{-}5}$ ${\llap{-}6}$ ${\llap{-}7}$ ${\llap{-}8}$ ${\llap{-}9}$ ${\llap{-}10}$ ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${10}$ ${\llap{-}2}$ ${\llap{-}3}$ ${\llap{-}4}$ ${\llap{-}5}$ ${\llap{-}6}$ ${\llap{-}7}$ ${\llap{-}8}$ ${\llap{-}9}$ ${\llap{-}10}$ $(1, -9)$